Answer:
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Step-by-step explanation:
The answer is a. hope this helps
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Answer:
see explanation
Step-by-step explanation:
note when x = - 3
(- 3)³ + 2(- 3)² + 4(- 3) + 21 = - 27 + 18 - 12 + 21 = 0
hence x = - 3 is a zero and (x + 3) is a factor and dividing gives
= (x + 3)(x² - x + 7)
For zeros equate to zero
(x + 3)(x² - x + 7) = 0
equate each factor to zero and solve for x
x + 3 = 0 ⇒ x = - 3
x² - x + 7 = 0 ← solve using quadratic formula
x = (1 ±
) / 2 = (1 ± 3i
) / 2
x =
± 
zeros are x = - 3, x =
±
the number of elements in the union of the A sets is:5(30)−rAwhere r is the number of repeats.Likewise the number of elements in the B sets is:3n−rB
Each element in the union (in S) is repeated 10 times in A, which means if x was the real number of elements in A (not counting repeats) then 9 out of those 10 should be thrown away, or 9x. Likewise on the B side, 8x of those elements should be thrown away. so now we have:150−9x=3n−8x⟺150−x=3n⟺50−x3=n
Now, to figure out what x is, we need to use the fact that the union of a group of sets contains every member of each set. if every element in S is repeated 10 times, that means every element in the union of the A's is repeated 10 times. This means that:150 /10=15is the number of elements in the the A's without repeats counted (same for the Bs as well).So now we have:50−15 /3=n⟺n=45